Accordingly, as shown in FIG. 1, a network N, in particular a telecommunications network, is made up of a set of equipment units E1, E2, E3, E4. It is generally associated with a network management system NMS, one object of which is to manage the behavior of the network, as function of requests submitted to it. In particular, each service request from a client can lead to reconfiguration of some of the network equipment. This reconfiguration is more widely known as “service provisioning”.
A conventional way to establish a dynamic link between requests (in particular service requests) and the required reconfigurations is to define a set of policies. This approach is recommended by the Internet Engineering Task Force (IETF) and is described in its RFC 3060 “Policy Care Information Model—Version 1 Specification”, February 2001, and RFC 3198 “Terminology for Policy-Based Management”, November 2001, for example.
The policies are managed by a Policy Manager PM. The policy manager PM sends the policies to policy decision points PDP1, PDP2 in accordance with distribution instructions. The distribution instructions are typically provided by the operator when the policies are created.
Finally, the policy decision points PDP1, PDP2 send the policies to policy enforcement points PEP1, PEP2, PEP3, PEP4. The policy enforcement points PEP1, PEP2, PEP3, PEP4 are associated with respective network equipment units E1, E2 E3, E4.
Because it uses policies, the network is able to adapt dynamically and automatically to requests, in particular service requests, as and when they arise.
However, this kind of approach has a major drawback in that it presumes that the distribution instructions are free of errors. This leaves the operator responsible for defining the policies and distribution instructions, which is a heavy responsibility, and for the time-consuming task of consulting a detailed map of the network in order to determine the capabilities of each network equipment unit.
In the event of an error, a policy enforcement point PEP will attempt to apply a policy to a network equipment unit that is incapable of enforcing it. This can interfere with the operation of the network unit and, on the other hand, lead to poor performance of the policy deployed by the operator.